Dual ground block



FIG. 1 is a top front left side perspective view of a dual ground block showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view,

FIG. 4 is a right side elevational view;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a top front, left side perspective view of the dual ground block shown in FIG. 1.

The broken lines illustrating a screw and nut in position is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a dual ground block, as shown and described. 